To mark its 15th anniversary as a band, the Grateful Dead played 15 nights at the Warfield Theatre in San Francisco in 1980. A poster by Dennis Larkins and Peter Barsotti was created for the show, but this is the postcard, front and back.

On the front, you can see that the marquee bears the same Bill Graham quote that was left on the Winterland marquee when the Dead closed that storied former ice rink on New Year's Eve, 1978/79: "They're not the best at what they do, they're the only ones that do what they do." The back basically encourages the crowd to behave and be grateful that the band agreed to play 15 nights in the small Warfield when they could have earned the same amount of money at a larger venue in just two.